Abstract:

In the production of fruit vinegar, the key step is to obtain acetic acid from alcohol by Acetobacter fermentation.
Available information has shown that the yield of acetic acid is affected by the starter culture, the fermentation environment
and alcoholicity. In this study, mulberry fruit wine was used as the raw material to brew fruit vinegar. Acetobacter
pasteurianus W6, isolated from Solid-State Vinegar Grains of Zhenjiang Hengshun, was used as the starter culture. Response
surface methodology (RSM) was used to optimize the fermentation conditions of mulberry fruit vinegar by analyzing
their effects on acetic acid production. The results demonstrated that the optimal conditions for mulberry fruit vinegar
fermentation were temperature of 32.5 ℃, initial alcoholicity of 7.5% (V/V), inoculum size of 10% (V/V), and shaking speed
of 160 r/min. Under these conditions, the yield of acetic acid was 5.85 g/100 mL. The experiments showed that W6 strain
was very active in producing acetic acid.

Key words: mulberry fruit vinegar, Acetobacter pasteurianus, fermentation conditions, response surface methodology